Spark plug cleaner with improved grit recycling

ABSTRACT

A spark plug cleaner is constructed as an upright canister with outwardly directed openings into which spark plugs are inserted. A vertically mounted motor driven impeller sucks grit from an axial center of the canister and flings it toward the spark plug sockets. A grit recovery floor is provided below the impeller and sockets and is configured concave upward. A suction guide fits coaxially over the collection floor and also slopes concave upward toward the center of the impeller. An annular vacuum channel is formed between the collection floor and the suction guide to concentrate impeller suction on spent grit as it falls to said collection floor and to increase grit velocity and density to the impeller.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to spark plug cleaners designed forworkshop use for amateur internal combustion engine maintenance.

2. Description of the Prior Art

A number of different types of internal combustion engine spark plugcleaners are commercially available for use by amateur mechanics. Somecommercially available embodiments are designed for a plurality of sparkplugs, while others accomodate but a single plug at a time. Virtuallyall conventional embodiments of such spark plug cleaners employ animpeller which rotates at a high speed and sucks grit axially toward theimpeller near its center and flings the grit outwardly toward a sparkplug socket or a plurality of sockets.

The spark plug sockets in conventional plug cleaners may be eitherhorizontally disposed, vertically disposed, or disposed at an anglebetween the horizontal and vertical. In those spark plug cleaners inwhich the plug sockets are mounted horizontally, the impeller rotatesabout a vertically disposed shaft. In such conventional devices, therehas been a consistent problem in recycling the grit to the impeller forreuse. Once the grit has inpinged upon the spark plug electrode toeffectuate cleaning, its momentum is quickly spent and it falls to thefloor of the confining container.

The principal difficulty in conventional systems arises in returning thespent grit to the impeller for reuse. In conventional devices withimpellers mounted about vertical axes a suction is created to draw thegrit upwardly for this purpose. However, in conventional devices it hasbeen extremely difficult to recycle grit to any significant degreebecause of the low suction that is normally produced by the motors andimpellers utilized. In one commercially available device, a helical orspiral ramp is defined about a vertical axis coaxial with the impelleraxis. The spiral about the vertical axis is intended to slopesiginficantly to allow the grit to reach the impeller quickly.Nevertheless, the vertical spiral configuration necessarily forces thegrit against the outer cylindrical confines of the spiral channel and asa consequence, the grit arrives at the impeller intake at a relativelylow velocity. The rotation of the impeller imparts additional velocityto the grit to increase its momentum to impinge upon the spark plugelectrodes. However, since the grit has very little momentum enteringthe impeller, its momentum as it strikes the spark plug electrodes isdeveloped almost entirely within the impeller.

Other spark plug cleaners have sought to enhance suction by providingrelatively narrow cylindrical tubes leading from the impeller inlet tothe collection floor of the plug cleaning chamber. In this fashion,suction is applied over a smaller cross sectional area, and hence agreater vacuum is produced. However, because suction is applied over asmall area there is a tendency for the grit at the collection floor inthe immediate vicinity of the suction tube to be quickly depleted, andhence the density of grit passed through the impeller is reduced.

SUMMARY OF THE INVENTION

It is an object of the present invention to improve both theconcentration and momentum of grit discharged through an impeller toimpinge against the spark plug electrodes to be cleaned in a spark plugcleaner. This is achieved by an improved construction which more rapidlyrecycles the grit. The spark plug cleaner of the invention employs acanister having one or more horizontally disposed spark plug sockets orports and an impeller mounted about a vertical axis for directing grittoward these ports. The spark plug cleaner is provided with a concaveannular collection floor located within the canister beneath the levelof the sockets and the impeller. The collection floor slopes upwardlytoward the interior of the confining canister walls, and also upwardtoward the impeller axis. A generally cone shaped convex suction guidefits coaxially over the collection floor where it slopes upward towardthe impeller. The narrow annular space between the suction guide andcollection floor forms a narrow annular vacuum channel leading from thecollection floor to the impeller to supply the impeller with grit tofling centrifically outward against the electrodes of spark plugspositioned in the sockets. Thereafter, the spent grit sinks again to thecollection floor. Because the floor slopes upward toward the canisterwalls, the spent grit slides downwardly and inwardly toward the mouth ofthe annular vacuum channel between the collection floor and the suctionguide. This maximizes the concentration of grit at the suction inlet.

The invention may be constructed to accomodate either one or a pluralityof spark plug sockets mounted in horizontal disposition. The impeller isformed with a plurality of radial or inclined vanes with openingstherebetween through which grit is expelled. The grit travels ingenerally horizontal tangential paths from approximately the impellerperiphery under the influence of the centrifugal force applied theretoby the impeller. The spark plug sockets are preferably aligned with thetangential paths of travel of the grit so as to maximize the directimpact of the grit on the spark plug electrodes to be cleaned. It isadvantageous to provide the impeller with a cylindrical shield with asingle outwardly directed opening therein through which grit can pass.The purpose of the shield is to maximize air flow with grit thru thesuction channel leading to it and to minimize air flow from the largerportion of the chamber immediately under the impeller.

The invention may be described with greater clarity and particularity byreference to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the inventionemploying a plurality of spark plug sockets.

FIG. 2 is a perspective view of an alternative embodiment of theinvention employing but a single socket.

FIG. 3 is a top view of the embodiment of FIG. 1.

FIG. 4 is a sectional elevational view taken along the lines 4--4 ofFIG. 3.

FIG. 5 is a sectional view taken along the lines 5--5 of FIG. 4.

DESCRIPTION OF THE EMBODIMENTS

FIG. 4 depicts a spark plug cleaner formed as a generally cylindricalcanister 10 having an upright cylindrical wall 12 closed at its ends bya generally disk-shaped top 14 and a generally disk shaped bottom 16. Aplurality of tubular spark plug sockets 18 are defined in the upperportion of the wall 12, all disposed in a common horizontal plane justbelow the top 14. Within the canister 10 a disk-shaped impeller 20 ismounted horizontally in the same plane as the sockets 18. The impeller20 is mounted for rotation about a vertical axle 22, located at thecenter of the device. The impeller 20 is driven in rotation by a smallelectric motor 24, located in the lower portion of the canister 10.Within the canister 10 there is a concave upward annular collectionfloor depicted at 26. The collection floor 26 slopes upwardly andoutwardly, in a surface 28 toward the upright wall 12, and upwardly andinwardly toward the impeller in an opposing surface 30 as depicted inFIG. 4.

A generally truncated, cone shaped suction guide 32 fits coaxially overthe collection floor 26 directly above the upwardly and inwardly slopingsurface 30. The sloping surface 30 of the collection floor 26 and thesuction guide 32 define therebetween an annular vacuum channel denotedat 34. The channel 34 leads from the collection floor 26 to the impeller20 to supply the impeller 20 with grit 36. The grit 36 is comprised ofsmall particles of sand or other abrasive which are sucked through thevacuum channel 34 and into the impeller 20 and are flung against theelectrodes 38 and 40 of spark plugs located in the sockets 18, such asthe spark plug 42 depicted in FIG. 4.

The canister 10 is formed of plastic. The upper section of the canister10 is a generally cup-shaped structure disposed in inverted fashion andfrom the outer wall of which sockets 18 protrude. The sockets 18 aretubular structures integrally formed with the canister 10. At the mouthsof the sockets 18 there are rubber disk shaped inserts 44 inset andglued into shoulders defined at the mouths of the sockets 18. The rubbergaskets 44 have a generally star-shaped configuration of cuts therein,as depicted in FIGS. 1 and 2. The star-shaped cuts divide the gaskets 44into a plurality of sector shaped flaps. These flaps may be forced asideby a spark plug 42 which is manually pushed into a socket 18. When thegasket flaps are forced aside by a spark plug, they leave the electrodes38 and 40 of a spark plug 42 in the path of grit flung centrifugallyfrom the impeller 20.

The lower portion of the canister 10 is also of a generally cup-shapedconfiguration. Near the bottom of the lower section there is a moldedannular power cord port defined by a collar 46 and a circular aperturewithin which an electrical switch 48 is restrained. The electricalswitch 48 is locked in position by threaded bushings 50 and 52, on theinside and outside respectively of the wall 12. The bushings 50 and 52engage an annular threaded sleeve 54 within which a spring biased pushbutton 56 resides.

The upper extremity of the lower section of the canister 10 is boundedby the collection floor 26, which is a molded plastic structure facingconcave upward and convex downward, as depicted in FIG. 4. At the innerextremity of the sloping surface 30 of the collection floor 26 there isa thickened section 60 with a mounting tab 61. A mounting screw 62extends through the mounting tab 61 and into a tapped hole in the upperend of the motor 24 to mount the motor in the canister 10. A fiber orfelt washer 63 serves as a protective device for the motor 24 under thethickened section 60 and above a motor bearing 65. One of the electricalleads of the connector cord 58 is connected to one power input contactof the motor 24, while the other is connected to the other power contactthrough the switch 48. The circuit is completed to drive the motor 24during the time that the pushbutton 56 is in the depressed condition.The electrical switch 48 closed by the pushbutton 56 remains on untildepressed again to turn the spark plug cleaner off. This allows theoperator to use both hands to rotate the plug 42 within the sockets 18for more thorough cleaning.

Mounted atop the motor shaft 64 is an enlarged axle 22 of sufficientdiameter to power the impeller 20. The upper end 66 of the impeller 20is a circular disk, while the lower end 68 is an annular disk. Theimpeller 20 includes a number of vanes 68 which are directed outwardlyfrom the axle 22 and are integrally formed therewith. The vanes 68 areeither radial or they may be curved. With either construction, the vanes68 define openings therebetween through which grit is expelledcentrifugally through tangential paths toward the cylindrical wall 12 ofthe canister 10. As is apparent from FIG. 3, the spark plug sockets 18are offset from radial alignment with the canister 10, and are insteadaligned with a tangential path of travel of the grit 36 from theimpeller 20.

At the underside of the annular bottom 68 of the impeller 20 there is anaxially extending annular collar 72 that extends downward outside of thesuction guide 32. The collar 72 forms a shield at the upper extremity ofthe vacuum channel 34 to maximize air flow with grit through the vacuumchannel 34 and to minimize air flow from the larger area of the chamberoutside the suction guide 32.

The upper and lower sections of the canister 10 fit snugly together asdepicted in FIG. 2, to create a relatively smooth surface at theinterior upright wall 12, so that spent grit is not caught between theupper and lower sections, but rather flows smoothly down the interiorsurface of the wall 12 to the curved surface 28 of the collection floor26.

In the operation of the invention, spent grit tends to collect in thelowest area of the collection floor 26 between the oppositely slopingsurfaces 28 and 30. Since the lower extremity of the suction guide 32terminates directly above this area, a narrow annular vacuum channel 34is formed at the mouth of the suction guide 32 and between the suctionguide 32 and the collection floor 26. Since the vacuum produced as aresult of rotation of the impeller 20 by the motor 24 is concentrated inthis small area, the particles of grit are swept swiftly upward throughthe vacuum channel 34 toward the axle 22 and toward the impeller 20.Because of the tendency of the grit to collect at the mouth of thesuction channel 34, a high density of grit is continuously supplied tothe impeller 20. Because of the narrow dimensions of the vacuum channel34, and because of the smooth arcuate curves of the suction guide 32 andthe sloping surface 30, the grit 36 arrives at the impeller 20 with agreat deal of momentum. Further momentum is imparted to the grit 36 bythe impeller 20 with the result that the grit 36 achieves a greatervelocity in impingment upon the electrodes 38 and 40 of the spark plug42.

With the enhanced grit concentration and the increase in grit velocity,the present invention is able to more effectively clean spark plugelectrodes in a significantly shorter time, as contrasted with prior artdevices. This is true both with respect to the embodiment designed toclean a single spark plug, depicted at 10' in FIG. 2, and also in themultiple spark plug cleaner 10 depicted in FIG. 1.

Both embodiments of the spark plug cleaner of the invention may bedriven from an automotive vehicle battery. Power is transmitted throughthe power cord 58 from color coded clamps 76 and 78, depicted in FIG. 1.Accordingly, the spark plug cleaner of the invention can be utilizedoutside, and is not dependent upon the availability of commercial a.c.power.

It should be understood that numerous variations and modifications ofthe invention are possible. The spark plug cleaner can be used not onlyto clean the spark plugs of automotive vehicles, but also spark plugsemployed in connection with other devices, such as boat motors,snowblowers and lawn mowers. Moreover, various alternative motormounting arrangements, canister constructions and spark plug socketconfigurations are possible. Accordingly, the scope of the inventionshould not be limited to the specific embodiments depicted in thedrawings, but rather is defined in the claims appended hereto.

I claim:
 1. A spark plug cleaner comprising:a housing having a confiningwall and a vertical axis and at least one spark plug socket extendinginto said confining wall in the upper portion thereof for receiving andholding a spark plug with electrodes directed inwardly relative to saidaxis; an impeller mounted on a shaft within said housing to rotate aboutsaid vertical axis at the level of said socket, said impeller comprisinga horizontally disposed circular upper disk and a parallel annular lowerdisk spaced therefrom by a plurality of vanes with outwardly directedopenings therebetween, said lower annular disk having a downwardlyextending collar outside of a central circular opening therein, anannular concave collection floor located below said socket andconverging upwardly and inwardly in a smooth, arcuate, curved slopingsurface toward said axis and upwardly and outwardly toward saidconfining wall, an annular suction guide located interiorally of saidconfining walls and having a smooth, arcuate, curved sloping surfacefacing convex inward toward said axis and toward said collection floorin spaced disposition therefrom and coaxial therewith to define anannular suction gap therebetween, whereby said collar of said lower diskoverlaps said suction guide and resides in close proximity thereto, andan electric motor for driving said shaft and said impeller to propelgrit therein outwardly toward said spark plug socket whereby spent gritfalls to said collection floor for recycling to said suction gap forreuse.
 2. A spark plug cleaner according to claim 1 furthercharacterized in that said electric motor is located below saidcollection floor and is connected to said impeller by a vertical shaftalong said vertical axis.
 3. A spark plug cleaning device comprising acanister having upright walls in which a plurality of spark plug socketsare defined at a common horizontal level, impeller means locatedinwardly of said spark plug sockets for rotation about a vertical axis,said impeller means being mounted on a shaft and having a horizontallydisposed circular upper disk and a parallel annular lower disk spacedtherefrom by a plurality of vanes with openings therebetween and anannular collar that extends downward from said lower disk about acircular opening therein, a motor for driving said shaft and saidimpeller, a concave collection floor located within said canisterbeneath the level of said sockets and sloping upward toward said uprightwalls and upward in a smooth, arcuate, curved sloping surface towardsaid impeller, and a suction guide facing convex toward said collectionfloor in spaced disposition therefrom and coaxial therewith andinteriorally of said upright walls and said suction guide and saidcollection floor together define therebetween an annular vacuum channelleading from said collection floor to said impeller to supply saidimpeller with grit to fling centrifugally outward against spark plugs insaid sockets, and to thereafter sink to said collection floor and saidcollar of said lower disk overlaps said suction guide and resides inclose proximity thereto.
 4. A spark plug cleaner according to claim 3further characterized in that said impeller is constructed withoutwardly directed vanes with openings therebetween through which gritis expelled in tangential paths, and said sockets are each aligned withone of said tangential paths.
 5. A spark plug cleaner according to claim3 further characterized in that said sockets are each equipped withflexible, penetrable coverings to allow the insertion of spark plugelectrodes therein, and to otherwise block said grit from escaping saidcanister.